Translating circuits



H. A. AFFEL TRANSLATING CIRCUITS March 2 1926.

Filed 06%.

' avwemtoi 1M J j/ t etenteu 2e HERMAN A. AFFEL, 0F BROOKLYN, NEW YORK, ASSIGNOR T0 AMERICAN TELEPHU'NE AND TELEGRAFE GOMPANY, A CORPORATION OF NEW YORK.

TRANSLATING CIRCUITS.

Application filed October 5, 1921. Serial No. 505,529.

To an whom it may concern:

Be it known that I, HERMAN A. Arrnii,

residing at Brooklyn, in the county ot' Kings and State of New York, have invented certain Improvements in 'iranslating Circuits, of which the following is a specification.

This invention relates to translating cir V cults, and more particularly to translating circuits adapted to suppress certain co1n-.

ponents' resulting frointhe translating operation.

Where-1a balanced type of vacuum tube modulator is employed. for the purpose of modulating carrier currents in accordance with signaling or oice currents it is possible to suppress in the output circuit either the uninodii lated carrier component or the modulating signal current. it is not possible by means ot-balanced type of circuit to suppressboth the carrier coou onent and the modulating component. lhis is for the reason that the balanced circuit is so arranged [hill] the tubes are connected cum'u laliveiylwi'lh respect to one of the input currents I current -but is connected to operate difieu entia'lly with respect to one otthe other input current; is arranged so that the tubes act euniu, lati'vely with respect to the modulating current, even though the tubesuiay be adjusted for thefgreatest modulating effect by operation upon the lower curved portion of the components of the curve will still be present to a su fiicie'ut extent to allow considerable amplification of the modulating frequency.

One of the objects of the present invention is to balance out by auxiliary means the component transmitted through the modulator by reason of this straight amplification etlect. in the modulation circuit. This may be done, forexai'nple, by passing a certain amount or the input modulating energy through. an auxiliary vacuum tube circuit. in. which the adjustment is such that the operation is mainly that of amplification, the amplified energy of the modulating frequency being applied to the output circuit in such a Way as to oppose the energy due to the amplifying effect of the tubes.

The above object, as well as other objects of the invention, may be attained by means of various organizations an example of that is, the carrier or the modulating! ii, for example, the circuit.

which is set forth iuthe following description and illustrated in the single figure of the accompanying drawing.

teierring to the drawing, M and M designate the modulating vacuum tubes connected in a duplex balanced circuit of the general type disclosed in the United States patent to John E. Carson, No. 1,343,307 of June 15, 1920. In accordance with the principles of said patent the carrier frequency 0 may be applied to the common path of the two grid circuits so that thislrcquency will be balanced out so far as the output circuit of the tubes is concerned. The voice or other signaling frequency o is serially applied to the two grid circuits through the ancing actiou-fekes 'place.

1 -"While it; isitiuelj-tliat'. the tubes will be adjusted to Workupon the-lower curved part of the characteristic curve in order to emphasize the modulating characteristics of tubes; me-amplifying effect will San characteristic curve, the linear amplification be'presente In order to'neutralize the coin- .pohent o withires pect to the outgoing circuit 14 which'is associated Iwith the output sides oithe modulating tubes lli andlld through the primary windings 15 and 16 and secunder) winding 17, an auxiliarytube A is provided. Thistubehhas its input circuit associated with the source of modulating rnergy through a Winding 13 inductively arunged with respect-to the winding 10. its output circuit is associated with the outgoing circuitls through v,e Winding 18 inductively connected with the winding 17., The tube A is arranged to operate upon the straight or amplifying portion of the characteristic curve, and It-S amplification con stant isso" adjusted that the energy of frequency i: applied to the input circuit 0% the tube will appear in the output circuit with the same amplitude as the energy appearing in the output circuit ofithe modulator due to the 'amglifying effect of the modulating tubes. y properly poling the transformer windings the amplified energy from the tube A will be equal in magnitude but opposite in sign to the amplified energyof modulating frequency in the output circuit of the modulator. Consequently the component of frequency 0 will be prevented from passing to the circuit 14 and only the side frequencies c o and c 0 will be present in said circuit.

The general action above described may be considered as a method in which two translating devices are employed, one operating in such a manner that its characteristic is chiefly non-linear, so that the modu lating action predominates; the other translating device operating in such amanner that its characteristic is chiefly that of an amplifier, that is, linear; the connections being so arranged that the linear components remaining in the circuit of the first translating device, whose action is desired to be essentially non-linear, are balanced out by proper adjustment of the linear components of the circuit of the second translating device. The resultant action in the combined translating circuit is therefore more purely nondinear than that obtainable by the use of the first circuit alone.

It will be obvious that the general principles herein disclosed may be embodied in many other organizations widely different from those illustrated without departing from the spirit of the invention as defined in the following claims.

\Vhat is claimed is:

1. In a translating system in which two llftilSlJliil'l" devices are em 10 ed one having a characteristic which is chiefly non linear and the other having a characteristic which is chiefly linear, the method of transmission which consists in subjecting energy to the action of the device whose characteristic is chiefly non-linear, thereby producing in the out-put of said device energy components due to its non-linear characteristic and other energy components due to the linear component of its characteristic, and subjecting a portion of the energy applied to said first mentioned translating device to the action of. the translating device having the linear characteristic, the amount of energy so subjected being of such value as to produce translated energy equal in value to the components resulting from the linear action of said first translating device, and impressing the translated energy upon a transmission medium carrying said components resulting from the linear action of said first translating device but imoppesite phase relation thereto.

2. In a translating system in which a translating device is employed, having a characteristic which is chiefly non-linear, the

method of transmission which consists in subjecting energy to the action of said device whose charac'teristic is chiefly nonlinear, thereby producing in the output of said device energy components due to its non-linear characteristic and other energy components due to the linear component of its characteristic, and in suppressing the energy components due to the linear action by applying to a transmission medium carrying said components an amount 01' the subjected energy equal in value to said comonents due to the linear action of the trans- .ating device, the energy thus applied to the transmitting medium being opposite 1n phase to the energy to be suppressed.

3. In a translating system employing a balanced modulator circuit in which two translating devices having chiefly nonlinear characteristics are associated with certain input frequencies applied differentially with respect to the translating devices, and other input frequencies applied cumulatively with respect to the translating devices whereby the output current contains modulated component corresponding to said second mentioned input frequencies, but no component corresponding to said first men tioned input frequencies, the method of suppressing said first mentioned output component which consists in applying to a transmission medium carrying said unsurpressed components energy of the corresponding input frequency or frequencies, said applied energy being equal in amount and opposite in phase to said unbalanced component in the output of the modulator circuit.

4. In a translating system employing a translating device having a linear character istic and a balanced modulator circuit in which two translating devices having chiefly non-linear characteristics are associated with certain input frequencies applied ditferentially with respect to the translating devices, and other input frequencies applied cumulatively witlrrespcct to the translating devices whereby the output current contains modulated component corresponding to said second mentioned input frequencies, but no component corresponding to said first men tioned input frequencies, the method of suppressing said iirst mentioned output component which consists in subjecting energy of the corresponding input frequency or frequencies to the action of the translating device having a linear characteristic, the amount of energy so subjected being of such value as to produce translated energy equal in value to the unbalancedmodulator components, and' impressing the translated energy upon a medium carrying said unbalanced components but in opposite phase relation thereto.

5. In a translating system, a balanced modulator circuit coi'nprising a pair of meagre outgoing circuit upon which the output energy oi thcv modulator is applied, and means to in'iprcss upon said outgoing circuit, 1ndepcndcanly of said modulator, energy rom sai' cumulatively applied source, said in ans translating the energy from said sou....:e Without substantial change in Wave form.

6. .lln a translating system, a balanced modulator circuit comprising a pair of il'flllfzillllllllg devices, a source of energy applied. dill'erentially with respect to said translating devices, and another source of energy applied cumulatively with respect thereto, whereby the output energy of the modulator will contain a component corresponding to the latter source but no compouent corresponding to,the former source, an outgoing circuit upon which the output energy the modulator is impressed, and means for imprersino upon said outgoing c rcuit, independently of said modulator, 3y from said cumulatively applied 130M151, with such amplitude and phase relation neutralize the cfi'ects of the com.- ponent of: the outputcurrent of the moduetor correspimtli'zm; to said cui'nulatively a sou cc, said means translating the 1 y i said source without substant hange in wave form.

i. la a. translating system, a balanced modulator circuit comprising a pair oi translating devices, a source of energy applied differentially with respect to said. mans-lilting devices, and another source of energy applied cumulatively with respect thereto wherehy the output energy of the modulator will contain a component corresponding; to the latter source but no compon nt corresg'ionding to the former hour-cc, an outgoing circuit upon which the output energy of the modulator is impressed, an auxiliary translating device, nieansto apply a portion oi. the energy Erom said cumulatively applied source to saidauxiliary translating device for translation without substantial change in wave form, and means to apply the output energy of saidnnxiliary translating device upon said outgoing circuit in such phase relation as to neutralize the ell'eets oi the component of the output til current of the modulator corresponding to said cumulatively applied source.

8,111 a translating system, a, modulating device comprising a translator whose characterist e is chiefly non-linear, a source of energy applied differentially with respect to said translator nd a source of energy applied cumulatively thereto, so that a comi ponent will be present in the output current of the translator corresponding to said last mentioned source, but no component will be present corresponding t3 the, first mentioned source, an auxiliary translator Whose char aeteristie is chiefly linear, means to impress energy from said second mentioned source upon said last mentioned translator, an outgoing circuit, means to impress the output energy from said modulator upon said outgoing circuit, and means to impress the en.-

orgy from the translator having the linear characteristic upon said outgoing circuit in opposite "phase relation to the componentof the modulator current corresponding to the source applied cumulatively with respect to the translator having the non-linear characteristic.

9. In a translating system, a modulator, including two translating devices having ehiclly non-linear characteristics,'said translating devices being arranged in a balanced circuit, a source of energy applied differ entially to said translating devices, and a second sourceof energy applied eumula-' tivcly with respect to said translating devices, whereby the output current of the modulator will include a component corresponding to said second mentioned source, but no component corresponding to the first mentioned source, an auxilia v translating device having a linear characteristic, means to impress upon said last mentionerlhtranslating device energy from said second source, an outgoing circuit, means to impress the energy of theoutput current of the modulator uponsaid outgoing circuit, and means to impress energy from thotransl vice having the linear characteristic. upon sting do said. outgoing circuit in opposite phase r lation to the component of the output rent of the modulator corresponding to the second source,

In testimony whereof, I have signed my name to this specification this 21st day of September 1921.

HERMAN A. AFFJL. 

